Fiber cement product comprising at least one profiled surface

A method for increasing hydrophobicity of a fiber cement product, said method comprising the steps of

• providing a fiber cement product comprising at least one profiled surface where grooves are milled, said grooves each having a depth in the range 0.15 mm to 1 mm and a maximum width at a bottom of the groove in the range 2 mm to 20 mm;
• and
• applying a hydrophobation agent to the at least one profiled surface
• to obtain fiber cement product having a water take up of less than 1.5 mL after 48 hours as measured by the RILEM Test No 11.4 in horizontal application,
• wherein the hydrophobation agent is water free and the combination of a silane-based liquid comprising at least one silane of the formula SiR4 with each of the four R-groups independently being an organic group, three of the R-groups being selected from ethoxy or methoxy groups and the fourth R-group being a branched or linear hydrocarbon chain of an octyl, isobutyl or methyl group, and at least one oligomer siloxane of the formula H(R2SiO)nOH with each of the R-groups independently being an organic group;
• and
• allowing said silane-based liquid to penetrate the at least one profiled surface without leaving visual traces.